1. Field of the Invention
This invention relates to a system for measuring and outputting the execution time of each of the instructions of an operation program in an industrial automated apparatus such as an industrial robot or NC machine tool.
2. Description of the Prior Art
In an industrial automated apparatus such as an industrial robot, tact or operating time is an important factor which decides the production cost of a manufactured produced. In case of an industrial robot, operation or robot motion is controlled by an operation program. Operating time differs depending upon the method of parallel operation involving the path of motion, the jig, etc. Accordingly, time is wasted if the content of the operation program is inappropriate.
In order to search for locations in the program where wasted time occurs, the conventional practice is to measure the operating time of a robot by any of the following methods:
(1) Operating time is measured by a stop-watch or the like while observing the motion of an element such as the robot arm.
(2) The input signal to a servomotor or the like is measured using a device such as a pen recorder.
(3) An instruction for output to a display unit is temporarily inserted before or after an instruction to be measured, and the instruction is measured using a stop-watch, pen recorder, etc.
(4) A function such as one which returns time is temporarily inserted before or after an instruction to be measured, and the instruction is then measured.
Certain problems are encountered in the aforesaid methods. Specifically, in method (1), (a) measurement errors arise owing to reliance upon visual observation, thereby making high precision measurement impossible; (b) an instruction involving rapid motion cannot be measured; and (c) instructions whose associated motions are not visible to the eye, such as arithmetic and logical instructions, cannot be measured.
In method (2), (a) an instruction which operates a servomotor generally is executed frequently, and therefore it is difficult to specify the operation of the instruction whose execution time is to be measured; and (b) instructions such as arithmetic and logical instructions are not outputted to the exterior of the system and therefore cannot be measured.
In methods (3) and (4), (a) it is necessary to rewrite the operation program whenever measurement is performed, and therefore the burden on the measurer is great; and (b) the greater the number of times rewriting is performed, the higher the possibility that bugs will develop in the program.